I don't think that I am. I don't think that they want to be treated like they're 5, but I do think they don't want to put thought into it. We're training ourselves to offload critical thinking and I was surprised to see it driving the conversation here.
I took it to mean something like, "I won't understand an abstruse Ph.D.-level explanation of what happened. I need an explanation geared toward the layperson."
In fact, I think that's closer to the essence of ELI5--as opposed to literally explaining something at the 5 year old level.
I suppose you can quibble about using the initialism, ELI, but only if you're advocating for people who might be unfamiliar with its use. Otherwise, I don't understand your complaint.